Molded plastic leaching chambers are widely used for dispersing wastewater into soil and other media. Typically, a trench is cut in soil, and a string of interconnected straight 4 to 8 foot long arch shape cross section chambers is buried in the soil. Typically, the chambers have mating ends, and the end of a second chamber overlaps and or latches to the end of a first chamber. In common leaching systems water flows within the chambers by gravity. Thus, a string of chambers must have a slight pitch with respect to the horizontal plane, so the wastewater flows from one end of the string to the other. Whenever possible, chamber strings run along a more or less straight line.
When a string of chambers is installed on a sloping piece of land, the usual aim will be to run the strings of chambers transverse to the direction of the slope. Often, this demands that the string follow a curving or serpentine path, along the curving contour of a hillside. There are other instances where strings of chambers must follow a not straight path. For instance, an obstruction such as a boulder or other object may be encountered. Then, what would have desirably been a straight string must instead follow a deviating path, to pass around the obstruction. Thus, there has been a continuing need for connecting together chambers so that a chamber string approximates a curve in various degrees.
In most commercial chambers the fit at the joint between chambers is loose enough to allow some angling between chambers, so the string can follow a curving path. However, usually the amount of angling at each chamber is a few degrees at best, e.g. plus or minus 3 degrees. When more curving has been needed, various approaches are taken. A common solution has been to fit chambers with end plates which accept pipes, and connect adjacent chambers with pipes and common angled plumbing elbows. However, this entails an associated cost of additional parts and labor. Another approach has been to provide chambers with preformed angled ends. See U.S. Pat. No. 5,588,788 to Nichols and U.S. Pat. No. 5,669,733 to Daly et al. Analogously, short angled adapters, shaped in cross section like chambers, have been used. However, when using angled chambers and adapters it is a problem to have on hand the right chamber angle for the particular use. The need for chambers and adapters with different end angles raises plastic molding die costs and costs and nuisance of carrying inventory within the chamber distributor system and end user system.
Thus, there is a need for a means for connecting chambers at a chosen angle, according to the instant demand during a field installation. In some applications relatively small angles of adjustment are sought; in other instances there is a desire for a large range of angling, up to 90 degrees plus or minus. While the primary need is for leaching chambers, there is a use for angling of chambers used in other applications, such as for handling storm waters, or for chambers which provide voids within the earth for other reasons. Any means, whether a separate unit, or integral with the chamber, must have performance consistent with that demanded of chambers, for instance, insofar as being strong, durable, and inhibiting the infiltration of soil into the interior of a string of chambers. It must be economical and easy to use.